BR102017014825B1 - ALLOY COMPOSITION, AND, ALLOY COMPOSITION FORMED ARTICLE - Google Patents

Abstract

ALLOY COMPOSITION, AND, ARTICLE An alloy composition that includes about 1 to about 9 atomic percent aluminum (Al), about 25 to about 33 atomic percent titanium (Ti), about 10 to about about 33 atomic percent vanadium (V), about 5 to about 10 atomic percent zirconium (Zr), and about 25 to about 33 atomic percent niobium (Nb).

Description

FIELD

[001] This application generally relates to alloy compositions for use at high temperatures and, more particularly, to multiprinciple element alloy compositions for high temperature applications, and even more particularly to aluminum-aluminum alloy compositions. titanium-vanadium-zirconium-niobium (Al-Ti-V-Zr-Nb).

FUNDAMENTALS

[002] Several aerospace applications require the use of superalloys due to their mechanical strength and resistance to flow at high temperatures. For example, superalloys are incorporated into various aircraft structural components, particularly structural components exposed to high temperatures, as well as aircraft engines (eg turbine blades).

[003] The nickel-based superalloy Inconel 625 is one of the most commonly used superalloys for high-temperature space applications. Inconel 625 includes nickel (Ni) as the major alloying element, with additions of chromium (Cr), molybdenum (Mo) and niobium (Nb), among other possible elements. Because nickel is relatively heavy compared to other major alloying elements (eg titanium (Ti)), Inconel 625 is relatively dense, thus compromising its strength-to-weight ratio.

[004] For aerospace applications at even higher temperatures, the niobium-based alloy C-103 is commonly replaced with Inconel 625. C-103 includes niobium (Nb) as the main alloying element, with additions of hafnium (Hf) and titanium (Ti). However, C-103 is also relatively dense and has lower strength than Inconel 625.

[005] Thus, the high-temperature alloys currently available for structural applications offer strength, but at the expense of significant weight. With the current state of development of single-principle element alloy systems, a 10 to 15 percent increase in specific strength is considered difficult to achieve and is generally not cost-effective.

[006] Consequently, those skilled in the art continue to undertake research and development efforts in the field of alloy compositions.

SUMMARY

[007] In one embodiment, the described alloy composition includes, for example, about 1 to about 9 atomic percent aluminum (Al), about 25 to about 33 atomic percent titanium (Ti), about from 10 to about 33 atomic percent vanadium (V), about 5 to about 10 atomic percent zirconium (Zr), and about 25 to about 33 atomic percent niobium (Nb).

[008] In another embodiment, the described alloy composition includes, for example, about 2 to about 8 atomic percent aluminum (Al), about 25 to about 33 atomic percent titanium (Ti), about from 10 to about 33 atomic percent vanadium (V), about 5 to about 10 atomic percent zirconium (Zr), and about 25 to about 33 atomic percent niobium (Nb).

[009] In another embodiment, the alloy composition described includes, for example, about 2 to about 8 atomic percent aluminum (Al), about 27 to about 31 atomic percent titanium (Ti), about from 15 to about 30 atomic percent vanadium (V), about 6 to about 10 atomic percent zirconium (Zr), and about 27 to about 31 atomic percent niobium (Nb).

[0010] In yet another embodiment, the disclosed alloy composition includes, for example, about 3 to about 8 atomic percent aluminum (Al), about 28 to about 30 atomic percent titanium (Ti), about 20 to about 30 atomic percent vanadium (V), about 6 to about 9 atomic percent zirconium (Zr), and about 28 to about 30 atomic percent niobium (Nb).

[0011] Other embodiments of the multiprinciple element alloy composition will become apparent from the following detailed description, the accompanying drawings, and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a photograph of an ingot having the described multi-principle element alloy composition; Figures 2A and 2B are X-ray diffraction patterns of as-melted alloys having the described multi-principle element alloy composition (Figure 2B) and an exemplary comparative composition (Figure 2A); Figures 3A and 3B are scanning electron microscopy (backscatter electron detector) micrographs of as-melted alloys having the multi-principle element alloy composition described (Figure 3B) and an exemplary comparative composition (Figure 3A ); Figures 4A and 4B are X-ray diffraction patterns of annealed alloys having the described multi-principle element alloy composition (Figure 4B) and an exemplary comparative composition (Figure 4A); Figures 5A to 5D are scanning electron microscopy (backscatter electron detector) micrographs of annealed alloys having the described multi-principle element alloy composition (Figure 5C and 5D) and an exemplary comparative composition (Figures 5A and 5B ); Figure 6 is an X-ray diffraction pattern of the multi-principle element alloy composition after exposure treatment at 700°C for 7 days; Figure 7A and 7B are scanning electron microscopy (backscatter electron detector) micrographs of the multiprinciple element alloy composition after an exposure treatment at 700°C for 7 days; Figures 8A to 8D are conventional stress-strain curves under compression (at room temperature) of samples having the described multi-principle element alloy composition (Figure 8C and 8D) and an exemplary comparative composition (Figures 8A and 8B), wherein the samples were taken after an exposure treatment at 700°C for 7 days; Figures 9A to 9E are photographs of the samples used to generate the stress-strain curves of Figures 8A to 8D, including the initial samples (Figure 9A), tested samples having the described multi-principle element alloy composition (Figure 9D and 9E) and tested samples having exemplary comparative composition (Figures 9B and 9C); Figure 10 is a flowchart of an aircraft manufacturing and service methodology; and Figure 11 is a block diagram of an aircraft.

DETAILED DESCRIPTION

[0013] A multi-principle element alloy composition is described that can be used for applications used at high temperatures. Taking the nickel-based superalloy Inconel 625 as the reference, the described multi-principle element alloy composition offers a significant increase in specific strength at a lower density, while maintaining microstructural stability at high temperatures. Therefore, the multi-principle element alloy composition described may be well suited for use in various aerospace applications utilized at high temperatures, as well as in various non-aerospace applications.

[0014] In a first embodiment, a multi-principle element alloy having the composition shown in Table 1 is described. Table 1

[0015] Those skilled in the art will appreciate that various impurities, which do not substantially affect the physical properties of the multi-principle element alloy of the first embodiment, may also be present, and the presence of such impurities will not result in a leakage from the scope of the present invention. For example, the impurity content of the multiprinciple element alloy of the first embodiment can be controlled as shown in Table 2. Table 2

[0016] Thus, the multi-principle element alloy of the first embodiment may essentially consist of aluminum (Al), titanium (Ti), vanadium (V), zirconium (Zr) and niobium (Nb).

[0017] In a second embodiment, a multi-principle element alloy having the composition shown in Table 3 is described. Table 3

[0018] The impurity content of the multi-principle element alloy of the second embodiment can be controlled as shown in Table 2. Thus, the multi-principle element alloy of the second embodiment can consist essentially of aluminum (Al), titanium (Ti ), vanadium (V), zirconium (Zr) and niobium (Nb).

[0019] In a third embodiment, a multi-principle element alloy having the composition shown in Table 4 is described. Table 4

[0020] The impurity content of the multi-principle element alloy of the third embodiment can be controlled as shown in Table 2. Thus, the multi-principle element alloy of the third embodiment can consist essentially of aluminum (Al), titanium (Ti ), vanadium (V), zirconium (Zr) and niobium (Nb).

[0021] In a fourth embodiment, a multi-principle element alloy having the composition shown in Table 5 is described. Table 5

[0022] The impurity content of the multi-principle element alloy of the fourth embodiment can be controlled as shown in Table 2. Thus, the multi-principle element alloy of the fourth embodiment can consist essentially of aluminum (Al), titanium (Ti ), vanadium (V), zirconium (Zr) and niobium (Nb).

[0023] The multi-principle element alloys described can be used to manufacture various articles, such as aircraft parts and components, using traditional processes of castings or forgings, or hybrid processes, such as powder metallurgy processes, combined with part forging, or rolling, or extrusion, or welding (solid state (linear or rotational friction or inertia) or a melt or filler). Additionally, the multi-principle element alloys described can be used for various die-cast and near-dead casting fabrication processes, such as additive manufacturing laser, electron beam, plasma arc melting techniques, and sintering techniques. additive laser for powder metallurgy or electron beam.

EXAMPLES

[0024] Ingots of Al-Ti-V-Zr-Nb alloys were produced by 10 g arc melt fillers using high purity elements (minimum 99.9%) under an inert argon atmosphere (minimum 99.995% ) in a water-cooled copper crucible using a non-consumable tungsten electrode. Two alloys were produced, Example 1 and a Comparative Example, as shown in Table 6. Table 6

[0025] Prior to the preparation of the alloys, a titanium button used as a gas absorber was cast in order to remove residual oxygen, nitrogen and hydrogen from the furnace chamber. To ensure good chemical homogeneity, the ingots were turned over and remelted at least five times. Projections and volatilization of elements during melting were negligible and maximum mass losses were about 0.5%. An initial heat treatment was carried out at 1200°C for 24 hours. An exposure treatment at 700°C was carried out for 7 days to evaluate the stability of the microstructures at this temperature. This temperature was selected based on the upper limits of propulsion structures in commercial applications, and pushes it beyond the temperature range at which IT alloys are typically viable. In this sense, it is just a thermal exposure to simulate an application. Annealing and exposure treatments were carried out by introducing the samples into silica quartz tubes, fitted with zirconium chips and sealed under a primary vacuum 300 x 1 Pa (3 x 10-2 mbar) to prevent oxidation. At the end of the treatment duration, the tubes were removed from the oven and cooled in static air to room temperature.

[0026] The alloys as cast and annealed were characterized by conventional techniques. The microstructure and phase composition of the alloys were studied using X-Ray Diffraction (“XRD”), Scanning Electron Microscopy (“SEM”) and Energy Dispersive Spectroscopy (“EDS”) to determine the chemical composition. For SEM analyses, samples were hot mounted in phenolic resin, sanded with SiC sandpaper (#120 to #2400) and polished using a 1 μm colloidal alumina suspension. XRD analyzes were performed using a Panalytical Empyrean Diffractometer with Cu Kα Radiation on the polished cross sections of the samples. SEM investigations were performed using a HITACHI TM3000 tabletop microscope equipped with an energy dispersive detector (EDS).

[0027] The hardness values of the alloys were determined using a Bulher MicroMet 6020 tester using a Vickers-type notcher applying a load of 500 g for 20 s.

[0028] Compression tests at room temperature were performed on the exposed samples (700°C/7 days) using an EMIC machine of 100 kN, under a strain rate of 3 x 10-3 s-1. Samples measuring 4.0 mm in diameter and 8.0 mm in length were obtained by conventional machining from the exposed ingots.

Leagues in the Raw Fusion State

[0029] As shown in Figure 1, the ingots produced showed a metallic appearance with no indication of oxidation. In the initial tests, regions of unmelted material, probably niobium, were observed in the cross-sectional views, a problem that was solved by changing the melting procedure.

[0030] The XRD patterns collected from the as-melted alloys are shown in figure 2. The comparison example alloy (figure 2a) is mainly composed of a BBC phase and other minor phase(s) (s), whose peaks are still not well identified. The X-ray diffractogram of the alloy from Example 1 is shown in figure 2B. The results indicate a BBC single-phase microstructured alloy based on the XRD results.

[0031] The microstructures of the alloys in the as-melted state are shown in figures 3A and 3B, and the EDS analysis (global and phase compositions) is shown in Table 7. Table 7

[0032] The comparative example alloy is composed of a matrix (point 1) and second (s) minor phase(s) dispersed in this matrix (point 2), enriched with Al and Zr. The alloy microstructure of Example 1 shows a segregated dendritic structure with no apparent presence of second phase(s). The interdendritic regions are enriched with Al and Zr, and partially depleted of Ti and Nb. These results are in good agreement and corroborate those obtained by XRD.

Annealed Alloys at 1200°C for 24 hours

[0033] In order to eliminate the segregation of microstructures in the as-cast state, annealing heat treatments were carried out at 1200°C for 24 hours. The XRD patterns of the homogenized alloys are shown in Figures 4A and 4B. One can observe, for the comparison example alloy, reflections related to the BCC phase and an increase in the intensity of the secondary phase(s). Example alloy 1 remains composed only of the BCC phase, not suggesting an important alteration in the microstructure.

[0034] Micrographs of the annealed samples are shown in figures 5A to 5D. The microstructure of the comparative example alloy (figures 5A and 5B) consists of a matrix (point 1) in which two smaller phases precipitate: (i) light gray particles (point 2) and (ii) dark gray particles (point 3 ). EDS chemical analysis (Table 8) revealed that the dark gray particles are enriched with Al, V and Zr, while the light gray particles are mainly composed of Al and Zr. Table 8

[0035] The example alloy 1 (figures 5C and 5D) presented as close to single phase. The matrix (point 1) corresponds to the BCC solid solution, however, smaller precipitates of Zr-rich particles (light gray point 2) are observed, mainly at the grain boundaries, based on EDS results (Table 8).

Alloys Exposed at 700°C for 7 Days

[0036] Figure 6 shows the XRD pattern of the alloy of Example 1 after exposure to 700°C for 7 days. Reflections from the BCC remain dominant, however, few additional peaks are observed, suggesting that some precipitation occurred from the previously annealed sample (1200°C for 24 h), where such peaks were not observed (see figure 4B).

[0037] Figures 7A and 7B show SEM-BSE images of the alloy of Example 1 heat-treated (700°C/7 days). The microstructure of the alloy consists of a main matrix (point 1) and two types of second phase particles: light gray particles (point 2) and dark gray particles, revealed at higher magnification (figure 7B). EDS chemical analysis (Table 9) showed that the light gray particles are rich in Zr. However, dark gray particles are too small to be accurately analyzed by EDS. Table 9

Density Data

[0038] Using the pi densities of pure elements (Ai) and the alloy compositions, the pmix density of Example 1 and the Comparative Example alloys were estimated using Equation 1:

[0039] The calculated densities are given in Table 10, as well as the current densities for Inconel 718, Inconel 625 and C-103. Table 10

[0040] As can be seen, the calculated densities of the alloy of Example 1 (6.2 g.cm-3) and of the alloy of Comparative Example (5.9 g.cm-3) are considerably lower than that of Inconel 625 (8.4 g.cm -3 ).

Hardness and Compression Test Data

[0041] The measured hardness values of the heat-treated alloys are given in Table 11.

[0042] After heat treatment at 1200°C for 24 hours, both alloys showed significant hardness values, around 5.0 GPa. Heat treatment at 700°C did not significantly modify the hardness value of the equimolar alloy. However, in the case of the alloy of Example 1, an important decrease was observed, from 4.7 GPa to 3.5 GPa, probably associated with a decrease in the amount of Al and Zr in the solid solution of the solid solution of BCC and consequent precipitation of secondary stages. This result shows the significant effect of solid solution hardening on the reinforcement of these alloys.

[0043] Table 12 shows hardness, density and specific strength (hardness/density) of the alloys produced as well as those of the reference alloys (Inconel 718; steel 15-5PH and C-103). Table 12

[0044] Figures 8A and 8B show stress-strain data under compression from two samples of the alloy of the Comparative Example. The lowest yield strength was 800 MPa, with essentially no plastic deformation until fracture. A result probably associated with the large volume and intrinsic characteristics of the secondary phases present in the microstructure of this alloy.

[0045] Figures 8C and 8D show stress-strain data under compression from two samples of the alloy of Example 1. The lowest yield strength was 650 MPa, however, now, an important plastic strain regime was observed. In figures 8A to 8D, “US” indicates the stress values at which cracks began to be observed.

[0046] Figures 9A to 9E show the samples machined for the compression tests (figure 9A); alloy parts of the Comparative Example after compression tests (Figures 9B and 9C); and alloy parts from Example 1 after compression tests (Figures 9D and 9E). The important plastic deformation exhibited by the example alloy 1 is clearly seen by inspection of figures 9D and 9E.

[0047] The dispersion of data from the different samples of the same alloy was somehow the expected consideration of the initial preparation of these alloys by button-arc melting and the microstructure in the intrinsic heterogeneous melting state. In general, heterogeneities are not eliminated only by heat treatments. To produce more homogeneous microstructures, subsequent plastic deformation process steps such as hot/heat lamination can be applied.

[0048] Consequently, the multi-principle element alloy composition described can be used in various applications used at high temperatures, such as a replacement for nickel-based superalloys such as Inconel 625.

[0049] Examples of the description can be described in the context of an aircraft manufacturing and service method 100, as shown in figure 10, and an aircraft 102, as shown in figure 11. During pre-production, the manufacturing method and service of aircraft 100 includes, for example, specification and design 104 of aircraft 102 and procurement of material 106. During production, manufacturing of components/subassemblies 108 and systems integration 110 of aircraft 102 takes place. Next, aircraft 102 may undergo certification and provisioning 112 in order to be placed into service 114. While in service by a customer, aircraft 102 is scheduled for maintenance and routine service 116, which may also include modification, reconfiguration, remodeling and the like.

[0050] Each of the processes of method 100 can be performed or executed by a systems integrator, a third party, and/or an operator (eg, a customer). For purposes of this description, a systems integrator includes, without limitation, any number of aircraft manufacturers and major system subcontractors; a third party includes, without limitation, any number of vendors, subcontractors and suppliers; and an operator can be an airline, leasing company, military institution, service organization, and others.

[0051] As shown in Figure 11, the aircraft 102 produced by the example method 100 includes, for example, a fuselage 118 with a plurality of systems 120 and an interior 122. Examples of the plurality of systems 120 include one or more than one system a propulsion system 124, an electrical system 126, a hydraulic system 128, and an environmental system 130. Any number of other systems can be included.

[0052] The described multi-principle element alloy composition can be employed during any one or more of the stages of the manufacturing method and aircraft service 100. As an example, components or subassemblies that correspond to the manufacture of components/subassemblies 108, systems integration 110, and or maintenance and service 116 may be fabricated or manufactured using the described multi-principle element alloy composition. As another example, fuselage 118 can be constructed using the multi-principle element alloy composition described. Also, one or more apparatus examples, method examples, or a combination thereof may be used during component/subassembly fabrication 108 and/or systems integration 110, for example, to substantially speed up assembly or reduce cost. of an aircraft 102, such as the fuselage 118 and/or the interior 122. Similarly, one or more of the system examples, method examples, or a combination thereof may be used while the aircraft 102 is in service, for example and without limitation, for maintenance and service 116.

[0053] The multi-principle element alloy composition described is described in the context of an aircraft; however, a person of ordinary skill in the art will readily recognize that the described multi-principle element alloy composition can be used for a variety of applications. For example, the described multi-element alloy composition can be implemented in various types of vehicles including, for example, helicopters, passenger ships, automobiles, marine products (boats, engines, etc.) and the like.

[0054] Other aspects are described in accordance with the following clauses: Clause 1. An alloy composition comprising: 1 to 9 atomic percent aluminum; 25 to 33 atomic percent titanium; 10 to 33 atomic percent vanadium; 5 to 10 atomic percent zirconium; and 25 to 33 atomic percent niobium. Clause 2. Alloy composition according to clause 1, wherein said aluminum is present at 2 to about 8 atomic percent; or wherein said aluminum is present at 3 to 8 atomic percent. Clause 3. Alloy composition according to clauses 1 or 2, wherein said titanium is present in 27 to 31 atomic percent; or wherein said titanium is present in 28 to 30 atomic percent. Clause 4. Alloy composition of any of clauses 1 to 3, wherein said vanadium is present in 15 to 30 atomic percent; or wherein said vanadium is present in 20 to 30 atomic percent. Clause 5. Alloy composition of any of clauses 1 to 4, wherein said zirconium is present in 6 to 10 atomic percent; or wherein said zirconium is present in 6 to 9 atomic percent. Clause 6. Alloy composition of any of clauses 1 to 5, wherein said niobium is present at 27 to 31 atomic percent; or wherein said niobium is present at 28 to 30 atomic percent. Clause 7. Alloy composition of any of clauses 1 to 6, consisting essentially of said aluminum, said titanium, said vanadium, said zirconium and said niobium. Clause 8. An article formed from the alloy composition of any of clauses 1 to 7. Clause 9. The alloy composition of any of clauses 1 to 8 consisting essentially of: said aluminum in 2 to 8 atomic percent; said titanium at 27 to 31 atomic percent; said vanadium in 15 to 30 atomic percent; said zirconium in 6 to 10 atomic percent; and said niobium at 27 to 31 atomic percent. Clause 10. Alloy composition according to clause 9, wherein: said aluminum is present in 3 to 8 atomic percent; or said titanium is present at 28 to 30 atomic percent; or said vanadium is present at 20 to 30 atomic percent; or zirconium is present at 6 to 9 atomic percent; or said niobium is present at 28 to 30 atomic percent. Clause 11. Alloy composition of any of clauses 1 to 10, consisting essentially of: said aluminum in 3 to 8 atomic percent; said titanium in 28 to 30 atomic percent; said vanadium in 20 to 30 atomic percent; said zirconium in 6 to 9 atomic percent; and said niobium at 28 to 30 atomic percent. While various embodiments of the multi-principle element alloy composition have been shown and described, modifications may occur to those skilled in the art in reading the description. The present application includes such modifications and is limited only by the scope of the claims.

Claims (9)

1. Alloy composition, characterized by the fact that it consists of: 1 to 9 atomic percentage of aluminum; 25 to 33 atomic percent titanium; 10 to 33 atomic percent vanadium; 5 to 10 atomic percent zirconium; and 25 to 33 atomic percent niobium. 2. Alloy composition according to claim 1 characterized by the fact that said aluminum is present in 2 to 8 atomic percentage; or wherein said aluminum is present in 3 to 8 atomic percent. 3. Alloy composition according to claim 1 or 2, characterized in that said titanium is present in 27 to 31 atomic percentage; or wherein said titanium is present at 28 to 30 atomic percent. 4. Alloy composition according to any of claims 1 to 3, characterized in that said vanadium is present in 15 to 30 atomic percentage; or wherein said vanadium is present at 20 to 30 atomic percent. 5. Alloy composition according to any of claims 1 to 4, characterized in that said zirconium is present in 6 to 10 atomic percentage; or wherein said zirconium is present in 6 to 9 atomic percent. 6. Alloy composition according to any of claims 1 to 5, characterized in that said niobium is present in 27 to 31 atomic percentage; or wherein said niobium is present at 28 to 30 atomic percent. 7. Alloy composition according to any one of claims 1 to 6, characterized in that it consists of: said aluminum in 2 to 8 atomic percentage; said titanium at 27 to 31 atomic percent; said vanadium at 15 to 30 atomic percent; said zirconium in 6 to 10 atomic percent; and said niobium at 27 to 31 atomic percent. 8. Alloy composition according to claim 7 characterized by the fact that: said aluminum is present in 3 to 8 atomic percentage; or said titanium is present at 28 to 30 atomic percent; or said vanadium is present at 20 to 30 atomic percent; or zirconium is present at 6 to 9 atomic percent; or said niobium is present at 28 to 30 atomic percent. 9. Article, characterized by the fact that it is formed of an alloy composition consisting of: 1 to 9 atomic percentage of aluminum; 25 to 33 atomic percent titanium; 10 to 33 atomic percent vanadium; 5 to 10 atomic percent zirconium; and 25 to 33 atomic percent niobium.

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